In recent years, superconducting thin film materials have been developed, such as a superconducting tape wire having a superconducting film formed on a metal substrate. Methods of forming a superconducting thin film are broadly classified into gas-phase process and application process. The gas-phase process includes gas-phase process and chemical vapor deposition process, and the gas-phase process includes co-vapor deposition process, sputtering process and Pulsed Laser Deposition (PLD) process. The chemical vapor deposition process includes Metal Organic Chemical Vapor Deposition (MOCVD) process. The application process includes Metal Organic Decomposition (MOD) process. Unlike the gas-phase process, the MOD process provides a high material yield and does not require an expensive vacuum apparatus, and is therefore known as a low cost process. For example, there has been proposed a superconducting thin film material having a structure in which an intermediate layer is formed on a metal tape, an oxide superconducting layer is formed on the intermediate layer by the gas-phase process, and an upper oxide superconducting layer is further formed on the oxide superconducting layer by the MOD process (see Japanese Patent Laying-Open No. 2007-311234 (Patent Document 1)). It is noted that the MOD process is indicated as a metal organic deposition method in Patent Document 1.
According to Patent Document 1, the above-described structure in which a gas-phase-formed layer is formed as a superconducting film having a high orientation by the gas-phase process and an MOD layer is formed thereon as a superconducting film by the MOD process allows for the formation of a superconducting film having a high orientation and a high surface smoothness at low cost, thereby obtaining excellent properties such as a high critical current density (Jc) and a high critical current (Ic).